Amplitude-only calibration is very useful when trying to calibrate off a single point source at a time while there is unmodeled flux in the sky. This is exactly the situation we run into while trying to peel sources. Essentially, if you are trying to calibrate on a point source, but there exists a second source of similar flux elsewhere on the sky, a full complex gain calibration may move the second source to the location of the first source. This is impossible with an amplitude-only calibration.
However, it is important to remember that the amplitude-only calibration will be systematically offset from a full complex gain calibration. This is due to the fact that the amplitude-only calibration is unable to introduce small phases that correct for positional errors.
Related to #28
This implements amplitude-only calibration.
Amplitude-only calibration is very useful when trying to calibrate off a single point source at a time while there is unmodeled flux in the sky. This is exactly the situation we run into while trying to peel sources. Essentially, if you are trying to calibrate on a point source, but there exists a second source of similar flux elsewhere on the sky, a full complex gain calibration may move the second source to the location of the first source. This is impossible with an amplitude-only calibration.
However, it is important to remember that the amplitude-only calibration will be systematically offset from a full complex gain calibration. This is due to the fact that the amplitude-only calibration is unable to introduce small phases that correct for positional errors.